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Genetics Home Reference: your guide to understanding genetic conditions     A service of the U.S. National Library of Medicine®


Reviewed July 2011

What is the official name of the PTS gene?

The official name of this gene is “6-pyruvoyltetrahydropterin synthase.”

PTS is the gene's official symbol. The PTS gene is also known by other names, listed below.

What is the normal function of the PTS gene?

The PTS gene provides instructions for making an enzyme called 6-pyruvoyltetrahydropterin synthase. This enzyme is involved in the second of three steps in the production of a molecule called tetrahydrobiopterin (BH4). Other enzymes help carry out the first and third steps in this process.

Tetrahydrobiopterin plays a critical role in processing several protein building blocks (amino acids) in the body. For example, it works with the enzyme phenylalanine hydroxylase to convert an amino acid called phenylalanine into another amino acid, tyrosine. Tetrahydrobiopterin is also involved in reactions that produce chemicals called neurotransmitters, which transmit signals between nerve cells in the brain. Because it helps enzymes carry out chemical reactions, tetrahydrobiopterin is known as a cofactor.

How are changes in the PTS gene related to health conditions?

tetrahydrobiopterin deficiency - caused by mutations in the PTS gene

More than 45 mutations in the PTS gene have been found to cause tetrahydrobiopterin deficiency. When this condition is caused by PTS gene mutations, it is known as 6-pyruvoyltetrahydropterin synthase (PTS) deficiency. PTS deficiency accounts for more than half of all cases of tetrahydrobiopterin deficiency.

Most PTS gene mutations change single amino acids in 6-pyruvoyltetrahydropterin synthase, although some mutations insert or delete small amounts of DNA in the PTS gene or disrupt the way the gene's instructions are used to make the enzyme. Changes in 6-pyruvoyltetrahydropterin synthase greatly reduce or eliminate the enzyme's activity. Without enough of this enzyme, little or no tetrahydrobiopterin is produced. As a result, this cofactor is not available to participate in chemical reactions such as the conversion of phenylalanine to tyrosine. If phenylalanine is not converted to tyrosine, it can build up to toxic levels in the blood and other tissues. Nerve cells in the brain are particularly sensitive to phenylalanine levels, which is why excessive amounts of this substance can cause brain damage.

Additionally, a reduction in 6-pyruvoyltetrahydropterin synthase activity disrupts the production of certain neurotransmitters in the brain. Because neurotransmitters are necessary for normal brain function, changes in the levels of these chemicals contribute to intellectual disability in people with PTS deficiency.

Where is the PTS gene located?

Cytogenetic Location: 11q22.3

Molecular Location on chromosome 11: base pairs 112,226,365 to 112,233,973

(Homo sapiens Annotation Release 107, GRCh38.p2) (NCBI (

The PTS gene is located on the long (q) arm of chromosome 11 at position 22.3.

The PTS gene is located on the long (q) arm of chromosome 11 at position 22.3.

More precisely, the PTS gene is located from base pair 112,226,365 to base pair 112,233,973 on chromosome 11.

See How do geneticists indicate the location of a gene? ( in the Handbook.

Where can I find additional information about PTS?

You and your healthcare professional may find the following resources about PTS helpful.

You may also be interested in these resources, which are designed for genetics professionals and researchers.

What other names do people use for the PTS gene or gene products?

  • 6-pyruvoyl-H4-pterin synthase
  • 6-pyruvoyl-tetrahydropterin synthase
  • PTPS
  • PTP synthase
  • sepiapterin synthase A
  • sepiapterin synthesizing enzyme 1

See How are genetic conditions and genes named? ( in the Handbook.

What glossary definitions help with understanding PTS?

acids ; amino acid ; cofactor ; deficiency ; disability ; DNA ; enzyme ; gene ; molecule ; neurotransmitters ; phenylalanine ; protein ; toxic ; tyrosine

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.


  • Auerbach G, Nar H. The pathway from GTP to tetrahydrobiopterin: three-dimensional structures of GTP cyclohydrolase I and 6-pyruvoyl tetrahydropterin synthase. Biol Chem. 1997 Mar-Apr;378(3-4):185-92. Review. (
  • Dudesek A, Röschinger W, Muntau AC, Seidel J, Leupold D, Thöny B, Blau N. Molecular analysis and long-term follow-up of patients with different forms of 6-pyruvoyl-tetrahydropterin synthase deficiency. Eur J Pediatr. 2001 May;160(5):267-76. (
  • Kao CD, Niu DM, Chen JT, Shan DE, Lin YY, Wu ZA, Liao KK. Subtle brain dysfunction in treated 6-pyruvoyl-tetrahydropterin synthase deficiency: relationship to motor tasks and neurophysiological tests. Brain Dev. 2004 Mar;26(2):93-8. (
  • Leuzzi V, Carducci CA, Carducci CL, Pozzessere S, Burlina A, Cerone R, Concolino D, Donati MA, Fiori L, Meli C, Ponzone A, Porta F, Strisciuglio P, Antonozzi I, Blau N. Phenotypic variability, neurological outcome and genetics background of 6-pyruvoyl-tetrahydropterin synthase deficiency. Clin Genet. 2010 Mar;77(3):249-57. doi: 10.1111/j.1399-0004.2009.01306.x. Epub 2009 Jan 3. (
  • Liu TT, Chiang SH, Wu SJ, Hsiao KJ. Tetrahydrobiopterin-deficient hyperphenylalaninemia in the Chinese. Clin Chim Acta. 2001 Nov;313(1-2):157-69. (
  • Longo N. Disorders of biopterin metabolism. J Inherit Metab Dis. 2009 Jun;32(3):333-42. doi: 10.1007/s10545-009-1067-2. Epub 2009 Feb 9. Review. Erratum in: J Inherit Metab Dis. 2009 Jun;32(3):457. (
  • NCBI Gene (
  • Shintaku H. Disorders of tetrahydrobiopterin metabolism and their treatment. Curr Drug Metab. 2002 Apr;3(2):123-31. Review. (
  • Thöny B, Auerbach G, Blau N. Tetrahydrobiopterin biosynthesis, regeneration and functions. Biochem J. 2000 Apr 1;347 Pt 1:1-16. Review. (
  • Thöny B, Blau N. Mutations in the BH4-metabolizing genes GTP cyclohydrolase I, 6-pyruvoyl-tetrahydropterin synthase, sepiapterin reductase, carbinolamine-4a-dehydratase, and dihydropteridine reductase. Hum Mutat. 2006 Sep;27(9):870-8. (
  • Wang L, Yu WM, He C, Chang M, Shen M, Zhou Z, Zhang Z, Shen S, Liu TT, Hsiao KJ. Long-term outcome and neuroradiological findings of 31 patients with 6-pyruvoyltetrahydropterin synthase deficiency. J Inherit Metab Dis. 2006 Feb;29(1):127-34. (


The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? ( in the Handbook.

Reviewed: July 2011
Published: February 8, 2016